A comparison between two different automated total 25-hydroxyvitamin D immunoassay methods using liquid chromatography-tandem mass spectrometry

Introduction

Total 25-hydroxyvitamin D [25(OH)D] is the most reliable indicator of vitamin D status. In this study, we compared two automated immunoassay methods, the Abbott Architect 25-OH Vitamin D assay and the Roche Cobas Vitamin D total assay, with the liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Materials and methods

One hundred venous blood samples were randomly selected from routine vitamin D tests. Two of the serum aliquots were analyzed at the Abbott Architect i2000 and the Roche Cobas 6000’s module e601 in our laboratory within the same day. The other serum aliquots were analyzed at the LC-MS/MS in different laboratory. Passing-Bablok regression analysis and Bland-Altman plot were used to compare methods. Inter-rater agreement was analyzed using kappa (κ) analysis.

Results

The Roche assay showed acceptable agreement with the LC-MS/MS based on Passing-Bablok analysis (intercept: -5.23 nmol/L, 95% CI: -8.73 to 0.19; slope: 0.97, 95% CI: 0.77 to 1.15). The Abbott assay showed proportional (slope: 0.77, 95% CI: 0.67 to 0.85) and constant differences (intercept: 17.08 nmol/L; 95% CI: 12.98 to 21.39). A mean bias of 15.1% was observed for the Abbott and a mean bias of -14.1% was observed for the Roche based on the Bland-Altman plots. We found strong to nearly perfect agreement in vitamin D status between the immunoassays and LC-MS/MS. (κ: 0.83 for Abbott, κ: 0.93 for Roche) using kappa analysis.

Conclusion

Both immunoassays demonstrated acceptable performance, but the Roche Cobas assay demonstrated better performance than the Abbott Architect in the studied samples.Key words: 25-Hydroxyvitamin D, chromatography, immunoassay, methods, tandem mass spectrometry     

Decay of softwood in archaeological wooden artifacts

Hardwoods and softwoods were used side by side throughout Egyptian history, and importing softwoods that had an attractive color and texture was common. Over the decades, artifacts based on hardwoods and softwoods underwent deterioration phenomena, sometimes reaching either a level of brittleness or turning into a wood powder that may easily crumble. These levels of decay/degradation are often difficult to handle in terms of conservation treatments. To study or identify the reasons for decay has always been a point of interest for conservation purposes, but to assess decay and choose an appropriate treatment according to the state of preservation for the sake of keeping an artifact intact has become a subject of major importance. It is difficult at times to understand the deterioration process, because hardwoods and softwoods are different in structure, properties, and chemical composition. For this preliminary study, decayed samples from three commonly used softwood types, cypress (Cupressus sp.), cedar (Cedrus sp.), and pine (Pinus sp.), were identified and chosen. Scanning electron microscopy (SEM) of the samples indicated the degree of decay. Decayed and non-aged samples of the same wood type were analyzed using Fourier transform infrared spectroscopy (FTIR), and all the major carbohydrate and lignin bands were recorded. The strong hydrogen bonded (O–H) stretching absorption associated with water linked by hydrogen bonds to the –OH groups of cellulose and hemicelluloses in all decayed samples increased with decay. The brown powdery, fragile samples that had been evidently affected by microbial decay had a higher amount of lignin. The lignin/carbohydrate ratio was calculated and results compared. The increase of either lignin percentage or extractives in some of the samples had caused a darkening of color in both cypress and cedar samples, but the pine sample did not have the same texture and appearance. In cases where the lignin percentage decreased the samples had changed to a slightly lighter color. FTIR results explained the decay phenomena observed in SEM micrographs and helped assess wood decay and also confirmed results that had been previously obtained while applying traditional chemical analysis on wood.     

The Unique American Vision of Childhood

The present article scrutinizes “the unique American vision of childhood” (UAVC) as a phenomenon undermining high academic expectations and good work ethics, and in turn, contributing to the generally low academic achievement of U.S. students compared to their counterparts in other advanced countries. It starts with a definition of UAVC, followed by a discussion of how influential it has been. The article goes on to state three reasons why UAVC is troublesome and misleading, especially in an era of global competition. Excuses devised by the proponents for UAVC’s adverse effects are also revealed. The article ends with recommendations for future research and a conclusion elaborating on the consequences of UAVC and the likelihood that other countries might adopt a similar mentality.     

6- and 8-year-olds’ performance evaluations: Do they differ between self and unknown others?

The current study investigated kindergarteners and second graders’ ability to monitor and evaluate their own and a virtual peer’s performance in a paired-associate learning task. Participants provided confidence judgments (CJs) for their own responses and performance-based judgments (judgments provided after receiving feedback on their performance) for both their own and a virtual peer’s responses. For the performance-based judgments, children were confronted with their own or the peer’s answer as well as the correct answer. Additionally, participants were asked to credit their own and the peer’s correct and incorrect answers while facing feedback. Results indicate an age-related progression in metacognitive monitoring skills, with second graders differentiating more strongly in their confidence judgments between correct and incorrect responses compared to kindergarteners. Regarding performance-based judgments, children of both age groups provided higher judgments for correctly compared to incorrectly recognized items as well as for their own responses in comparison to the responses of the unknown child. Similarly, when crediting, participants of both age groups gave more credits for correct recognition than for incorrect recognition and for their own responses than for the peer’s responses. The significant interaction between age group and recognition accuracy for the crediting shows that second graders gave more credits for correctly recognized items while kindergarteners gave more credits for incorrect answers than the older children – primarily for their own incorrect answers. In conclusion, the study provides new insights into 6- and 8-year-olds’ evaluations of their own and an unknown child’s performance in a paired-associate learning task by showing that children of both age groups generally judged and credited responses in their own favor. These results add to our understanding of biases in children’s performance evaluations, including metacognitive judgments and judgments provided after receiving feedback.     

An analysis of teachers’ self-reported competencies for teaching metacognition

For successful reading experiences in native and/or foreign/second language, individuals need to benefit from not only cognitive strategies but also metacognitive strategies. Although research found reading comprehension and performance increase following metacognitive trainings, such findings may not transfer into mainstream classrooms as easily for several reasons. This study, therefore, aimed to disseminate the phenomenon of teaching metacognition with an emphasis on teacher’s instrumental role during classroom learning. More specifically, it investigated language instructors’ metacognition and their self-reported competencies for teaching metacognition. It also examined whether and how self-reported competencies changed following a professional development (PD) module of teaching for metacognition. Utilising Metacognitive Awareness Inventory (MAI) and think aloud protocols for instructional planning, this study found most participants were either highly metacognitive or metacognitive individuals. It was also found that most participants were initially not knowledgeable about and/or competent in teaching metacognition. Following PD, highly metacognitive teachers developed authentic lesson plans manifesting metacognition instruction while metacognitive teachers adopted similar instructional designs presented during the PD. Besides, half of the participants appreciated teaching metacognitively following the PD. Finally, under the light of these findings, future research and policy adjustments were proposed.     

Medical neglect of a child: challenges for pediatricians in developing countries

OBJECTIVE: To conceptualize the underlying causes of the medical neglect of children in a developing country and to provide suggestions for the management of neglect by pediatricians. METHODS: A case history of a 4-year-old boy from Turkey with neglect of the required treatment for acute lymphoblastic leukemia is used to examine the causes and management of medical neglect. Results: Although epidemiological studies on child neglect are lacking, this case exemplifies how in DEVELOPING countries, reasons for neglect or non-compliance with medical recommendations and the roles and actions taken by the health care and the social service systems may differ from western populations. Common to both western and developing countries, the characteristics of the child, family, and society may be reasons for medical neglect. However, cultural fatalistic beliefs profoundly present in the developing world may also contribute to the medical neglect of a child. Identification of the neglect, a comprehensive, multidisciplinary assessment emphasizing the strengths within the family and the society, and the determination of the pediatric team to act in the best interest of the child may result in resolution of the neglect even in circumstances where resources within systems are not sufficient. CONCLUSIONS: In developing countries, increased emphasis on child neglect, its prompt recognition and management within the pediatric profession as well as at a health care and social service system levels are needed to address this prevalent and potentially fatal child health problem.     

The Effects of a Teaching Methods Course on Early Childhood Preservice Teachers' Beliefs

This study examines the effectiveness of an educational methods course for changing early childhood preservice teachers' instructional beliefs. The teaching methods course emphasized constructivist teaching principles. Seventy-eight of the early childhood education preservice teachers who were enrolled in this course filled out the Teacher Belief Survey at the beginning and end of the 15-week course. The results of both quantitative and qualitative data analysis indicated that participation in the teaching methods course had significantly changed preservice teachers' beliefs. As a result of the course, preservice teachers' constructivist beliefs increased, and these beliefs became more concrete and coherent. Results are discussed in relation to the literature, and the implications of examining early childhood education programs are explored.     

Comparing the effects of different book reading techniques on young children’s language development

The purpose of this research study is to compare the effects of digital, dialogic and traditional reading on children’s language development aged 48–66 months. Fifty-six randomly selected children enrolled in three different classrooms in a public preschool in Turkey participated in the study. The three classrooms were again randomly assigned as digital, dialogic and traditional reading groups. During the reading activities, a total of 24 storybooks were read by each group every three times in 8 weeks. While the children’s language scores (the receptive and expressive language scores) resulted in a significant increase in dialogic reading, the children’s language scores in a digital and traditional reading group slightly changed during the intervention. Alternatively, qualitative data suggested that the interaction between teacher and children and between children and children were very limited in a digital and traditional reading group and that limited interaction during reading was the underlying cause of the insignificant increase in children’s language scores.

     

Problem-Based Learning in 9th Grade Chemistry Class: ‘Intermolecular Forces’

This research study aims to examine the effectiveness of a problem-based learning (PBL) on 9th grade students’ understanding of intermolecular forces (dipole–dipole forces, London dispersion forces and hydrogen bonding). The student’s alternate conceptions about intermolecular bonding and their beliefs about PBL were also measured. Seventy-eight 9th grade students were stratified by cognitive levels and then randomly assigned to experimental (PBL, 40 students) and control (lecture-style teaching, 38 students) groups. Following a preparatory lesson where activation and remediation of existing knowledge occur, a pre-test was given, and no significant difference was found between the two groups of students (p > .05). After the instruction was completed, a post-test and also a questionnaire related to the quality of the problem, the teacher’s role and group functioning were administered. Results from the post-test of both groups (p < .05) and questionnaire showed that PBL is affective on students’ achievement, remedying formation of alternate conceptions and also social skills.     

“It came alive outside my head.” Developing literacies through comparison: the reading of classic text and moving image

This article reports on a term's work with students in Initial Teacher Education (ITE) in which the adult classic text Silas Marner was studied in both written and film form ( Eliot, 1994 ; BBC/Fo, 1985 ). Through an extended consideration of the structures employed by different forms of narrative, students were invited to consider the knowledge and skills they brought to the development of their own response to different texts. Concurrently they were encouraged to consider the needs of their prospective pupils, as expert readers of moving image, and as novice readers of classic fiction. Crucial to the teaching and learning experience was the consideration of the different, expanding notions of literacy, including visual literacy, tele‐literacy and moving‐image literacy. A key consideration was the interrelationship between these, with narrative as the key link, and the exploration of how these literacies could be mutually supportive within the framework of ‘school’ literacy. The importance of paying explicit attention to the pedagogical practices that foster an engagement with and development of these different literacies was highlighted, as was the need to experience the reading of whole texts in order to foster the development of response.